The Bears (15-0) have made a meteoric rise in the poll, going from a team that didn't receive a vote in the preseason poll to one that received 55 first-place votes from the 65-member national media panel on Monday.
Baylor is the 59th school to be ranked No. 1 since the poll started in the 1948-49 season. The Bears will be tested on top right away, playing at West Virginia on Tuesday and at Kansas State on Saturday.
The Bears own wins over Oregon (No. 4 at the time, but playing without Dillon Brooks then), Xavier (No. 7 then) at home, and neutral-court wins over then-No. 10 Louisville and then-No. 24 Michigan State at the Battle for Atlantis in the Bahamas.
Coach Scott Drew was on ESPN's podcast Courtside with Katz and Coach Gon Monday and said the Bears should be No. 1.
"I think it goes to your body of work," Drew said. "We've played a very competitive schedule and we've been successful against well-coached and good teams. At this point, and with every poll you could argue about several different teams, with our top 25 wins and top 50 RPI wins and the fact we haven't lost yet, then yes, you can definitely make a case for the Baylor Bears."
Villanova, which received one first-place vote, had been No. 1 for the last five weeks, but the Wildcats (15-1) dropped to third after losing at Butler last week.
Kansas(14-1), No. 1 on eight ballots, moved up from third to second, giving the Big 12 the top two teams in the poll.
UCLA(16-1), which got the other first-place vote, stayed fourth.
Gonzaga(15-0), the only other unbeaten Division I school, and Kentuckyremained fifth and sixth, while Duke, Creighton, Florida State and West Virginia rounded out the top 10.
North Carolina was 11th, followed by Butler, Oregon, Louisville, Xavier, Arizona, Purdue, Wisconsin, Virginia and Notre Dame.
The last ranked teams are Saint Mary's, Cincinnati, Florida and Minnesota, with Kansas State and Southern California tied for 25th.
Minnesota moved into the rankings for the first time since 2012-13, when the Gophers were in the poll for 11 weeks, reaching as high as No. 9. Minnesota's arrival means that there's a father-son duo in the Top 25, with Louisville coach Rick Pitino and Minnesota coach Richard Pitino.
Kansas State was last ranked for two weeks in 2013-14.
Virginia Tech (12-3) dropped out from 21st after losses to NC State and Florida State. The Hokies had been ranked for just one week.
Indiana (11-5) was ranked 11th in the preseason poll and had reached as high as No. 3. But the Hoosiers' loss to Wisconsin last week was their third straight.
There are nine games this week between ranked teams. In addition to Baylor at West Virginia, the other game between top-10 teams is Duke at Florida State on Tuesday.
The Atlantic Coast Conference leads the way with six ranked teams while the Big 12, Big East and Pac-12 have four each.
The Associated Press contributed to this report.